A stitch in time...continuous supervision versus preventative maintenance-a new concept for petrochemical plants

Continuous supervision is a concept of preventative maintenance (PM) practices used in the German chemical industry. It has been accepted inclusion into the IEC 60079-17 standard. It is a process where periodic checks are mandated on explosion protected equipment by skilled personnel. The level of scrutiny of these checks are determined by an "executive technician" or engineering manager. The engineering manager must determine the frequency, duration, and severity of the checks based on his/her knowledge of the hazardous area environment, process area, and explosive protected equipment installed and advise the plant personnel to carry out those checks. With maintenance budgets shrinking, one way of providing continuous supervision or PM practices is by utilizing electrical monitoring and control systems (EMCs). EMCSs allow operators and technicians to monitor and diagnose the electrical systems controlling the petrochemical processes. These systems are complementary to the existing distributed control systems (DCS) that operate and monitor the petrochemical process.